Development of Novel Immobilization Supports of Lipase for Reactions in Organic Media: Seed Polymerization of Amphiphilic 2-[p-(1, 1, 3, 3-Tetramethyl-Butyl) Phenoxy-Polyethoxy] Ethyl Methacrylate Macromonomers

Abstract

To develop a novel support of enzymes for use in the enzymatic reactions in nonaqueous solutions, amphiphilic polymer particles which have 2-[p-(1, 1, 3, 3-tetramethyl-butyl)phenoxy-polyethoxy]ethyl groups (tert-C₈ΦE_n groups; n is the mean number of the ethylene oxide units) were synthesized by the seed copolymerization of styrene, divinylbenzene, and 2-[p-(1, 1, 3, 3-tetramethyl-butyl)phenoxy-polyethoxy]ethyl methacrylate (MAX-n). In seed polymerization, the mean number n of the tert-C₈ΦE_n group did not affect the monomer conversions and the amount of MAX-n introduced into the particles. Using Rhizopus delemar lipase as a model enzyme, the enzyme immobilization on the amphiphilic polymer particles was investigated. The specific hydrolytic activity of the immobilized lipase prepared with the amphiphilic polymer particles was higher than that of native lipase. When the amphiphilic particles synthesized using MAX-15.9 were used to immobilize lipase, the amount of lipase immobilized and the hydrolytic activity and the transesterification activity of the immobilized lipase were the highest. However, the organic solvent stability of the immobilized lipase prepared with the amphiphilic particles synthesized using MAX-4.39 was the highest.